Coaxial switch



Nov' 24,

Wfgj.

R' R FREI-:LAND

2914639 COAXIAL SWITCH Filed Aug. 2O 1957 wmmmfm ATTORNEYS United StatesPatent'lQ COAXIAL SWITCH Roya-en R. Freeland, oklahoma city, olea.

Application August 20, 1957, Serial No. 679,177 l16 claims. (cl.zoo-iss) Thisinvention relatesr to a new and improved coaxial switchAdesigned to couple either of two signals to a tele-- vision receiverwithoutinterference.

The invention comprises an outer tubular conductive casing withinwhichslides'a plastic barrel. In the middle of the barrel is mounted avleafclip contact which runs completely through the barrel. The switchingaction is accomplished by sliding the plastic barrel't'o either end ofthe tube Vto make contact with the coaxial terminals mounted ateach endof the tube.

Prior to this invention coaxial switches-'were known but therswitches'according to the prior art'are more costly to produce, notas longlasting,Y and not as easy to operate as the switch according' to thepresent invention. For example, one such switch inthe prior art has anouter cylindrical member and inner conductive cylinder supported by twoend members ofthe outer cylinderf' The switching action is accomplishedby sliding amovable contact 'along the inner cylindrical conductivemember.V Such an arrangement is subject to wear and the sliding contactoften sticks on the inner cylindrical member making switching actiondiihcul-t. This wear also resultsl in poor contact, thus giving rise tointerference with the signal `transmittedthrough the switch.

The objects and advantages of this invention can be better understoodwith reference to the following figures wherein:v f

Figure 1 shows an elevation view of the switch partly I Figure 3showsanother cross sectionthrough Figure 1.

Figure`4 shows an exploded view illustrating the various parts of theswitch in detail.

The switch consists of an outer cylindrical conductive casing 11 whichhas two slots 12 and 13 running longitudinally along the casingdiametrically opposite to one another. Mounted on each end of the casing11 are conductive caps 21 and 22 which fit over the casing 11. The capsare fastened to the casing by screws. Mounted respectively in the middleof the caps 21 and 22 are the coaxial terminals 14 and 15. These coaxialterminals have conductive surfaces, which are soldered to make contactwith the caps 21 and 22, and conductive inner contact members 24 and 25which are insulated from the outer surfaces. Fitting within the casing11 is a plastic insulating cylindrical barrel 16, which has a shorteraxial dimension than the casing 11. The barrel 16 has a smaller diameterthan the inner wall of the casing so as to make a loose lit therewith. Aleaf spring contact 27 is mounted in the casing between the plasticbarrel and the inner wall of the casing opposite the lower slot 13. Thisspring serves to press the barrel 16 against the upper inner wall of thecasing topositively locate the axial position of the barrel and providefriction to hold the barrel longitudinally in place in the barrel butwith a small enough force that the barrel may be slid without diticulty.A handle 17 is mounted with a screw 2. lit in the'barrel 11 and thishandle projects through the slot 12. vA third coaxialterminal 18"ismounted diametrically opposite/toV the handle 1-7 in the barrel 16. ThisterminalV1 makes a^n screw litE with the plastic barrel 1`6= and extendsthrough the hole' in the center of the spring contact 27 and the slot13. The terminal has' an outer conductive surface and a conductive innercontact member 26;.v which is insulated from the outer surface. Theouter conductive surface of the coaxial terminal has a' flange 28 whichApresses against the spring contact' 27' andV firmly mounts4 it against`thebarrel 16. The contact spring 27 has the additional function ofproviding a conductive path between the casing 11 and theE conductivesurface` of? the coaxial terminal 18. li/IountedS inthe middleofthe-plastic barrel 16 is a leaf clip contactassembly 20 which runsthroughout the length of th'e barrel and'has leaf clip contacts at eachend'of the barrel. vThe member 26 makes contact with the leaf clipcontact assembly in the exact center of the plastic barrel16. l

With-this construction, the barrel 16 can slide back and forthwithin thetube 11 and at one end of the barrel ybarrel' from one position 'totheother andY this sliding is accomplished by means ofthe knob 17.'v y

InV the preferred embodiment the casing and the barrelhave been shownlas cylindrical. However, they may .beYA oblong,l orany otherconfiguration. It is necessary,

however, that the inner walls of the casing have-the shapeof thedevelopment of a movementl straight line maintained parallelzto areference' line, so that thevbarrel will'-slidewithinl the-casing.'These and numerous other modifications can be made n the disclosedembodiment without departing from the spiritl and' scopey of. theinvention which is to be limited only as defined in the appended claims;

l. A coaxial switch comprising a conductive tubular lcasing having slots'defined therein running longitudinally on said cylindricalcasing, acylindrical-barrel made' of insulating material making a sliding fitwith theV inner walls of said casing having an axial dimension shorterthan said casing, a handle mounted on said barrel and projecting throughsaid one of said slots, a leaf clip contact member mounted in saidbarrel running axially throughout the length thereof, a conductormounted in said insulating member making contact with said leaf clipcontact member and projecting through the other of said slots, a firstconductive cap covering one end of said casing, a conductor mounted insaid cap 'but insulated therefrom and positioned so as to make contactwith said leaf clip contact member when said insulating member is slidto said one end of said casing, a second conductive cap covering theother end of said casing,- a conductor mounted in said second cap butinsulated therefrom and positioned so as to make contact with said leafclip contact member when said insulating member is slid to the other endof said casing.

2. A coaxial switch comprising anouter conductive casing having an innerwall whoseV surface is in the shape of a development of the movement ofa straight line which is constantly maintained parallel to a referenceline, an insulating member making a sliding tit with said surface of theinner wall of said casing, a first conductor mounted on said insulatingmember, a second conductor mounted on said casing positioned to makecontact with said rst conductor, and means to slide said insulatingmember within said casing to selectively make or break the conductivepath between said conductors.

3. A coaxial switch as recited in claim 2 wherein said second conductoris `nsulatedlfrom said casing.

4. A coaxial switch as recited in claim 2 wherein said casing has a slotdefined therein running in the same direction as said reference line andwherein Vsaid means to slide said insulating member comprises .a handlemounted on said insulating member and extending through said slot.

5. A coaxial switch as recited in claim 2 wherein said casing has a slotdefined therein runningv in the .same

direction as said reference line and wherein there is ai4 thirdconductor directly connected to .said and extending through said slot.

6. A coaxial switch comprising an outer conductive casing having aninner wall of which the surface is in the shape of a development of themovementofa straight line which is constantly maintained parallelto areference line, an insulating member making a sliding iit with saidsurface of the inner wall of said casing, a first conductor mounted onsaid insulating member, a second first conductor conductor mounted onsaid casing positioned to ContactV i said first conductor when saidinsulating member is `slid to a first position, a third conductormounted on vsaid casing positioned to contact said first conductor whensaid insulating member is slid to a second position and means to slidesaid insulating member between said iirstand second positions.

7. -Acoaxial switch as'recited in claim 6 wherein said second and thirdconductors are insulated from said casing.

8. A coaxial switch as recited in claim 6 wherein saidi casing has aslot defined therein running in the same direction as said referenceline and wherein said means to slide said insulating member comprises ahandle mounted on said member and extending through said slot.

casing has a slot defined therein running in the same direction as saidreference line and wherein there is provided a fourth conductor mountedon said insulating 9. A coaxial switch as recited in claim 6 whereinsaid member directly connected to said iirst conductor and i extendingthrough said slot.

10. A coaxial switch as recited in claim' 6 wherein said first conductorruns from one end of said insulating member to the other in the samedirection as said reference line and said second and third conductorsare positioned to contact said conductor at opposite ends of saidinsulating member.

ll. A coaxial switch as recited in claim 10 wherein said first conductorcomprises a leaf clip contact member.

12. A coaxial switch as recited in claim il wherein said casing has aslot defined therein running the same direction as said reference lineand wherein there is provided a fourth conductor mounted in saidinsulating member directly connected to said leaf clip contact member,said fourth conductor extending through said slot.

13. A coaxial switch comprising an outer conductive casing, aninsulating member making a sliding iit with the inner wall of saidcasing, a iirst contact member mounted in said insulating member, and asecond contact member mounted on said casing, positioned to make contactwith said first contact member, and means to slide said insulatingmember within said casing to selectively make or break the conductivepath between said contacts.

14. A coaxial switch as recited in claim 13 wherein there is provided aleaf spring mounted on said insulating member to press against the innerwalls of said casing.

l5. A coaxial switch comprising an outer conductive casing, aninsulating member making a sliding t with the inner Wall of said casing,a contact member mounted in said insulating member, a coaxial terminalhaving an outer conductive surfacerand an inner contact member insulatedfrom said surface, said terminal being mounted on said casing so thatsaid outer surface makes contact with said casing, said terminal beingpositioned so that said inner contact member of said terminal makescontact with said rst mentioned contact member, and means to slide saidinsulating member within said casing to ,make or break the conductivepathv between said iirst mentioned contact member and said inner contactmember of said coaxial terminal. f Y

16. Av coaxial switch as recited in claim 15 wherein a slot is dened insaid casing and thereis provided a conductive leaf spring having a holedefined therein, -a second coaxial terminal having an outer conductivesurface and an inner contact member insulated from said conductivesurface, said coaxial terminal having a flange and being mounted on saidinsulating member, said tlange pinning said leaf spring to saidinsulating member between said member and the inner wall of said casing,said leaf spring pressing against the inner wall of said casing, saidsecond coaxial terminal extending` through said slot.

References Cited in the tile of this patent UNITED STATES PATENTS2,550,921 Greene V May 1,- 1951

